1. Field of the Invention
The present invention relates to an arrangement for the support of a program plate, preferably for a timer, including a bottom plate with a support sleeve fastened thereto and which is preferably integrally formed with the bottom plate; in which the outer surface of the support sleeve forms a rotary bearing for a hub of the program plate; wherein the bottom plate includes a hole therethrough which forms a guide for a drive take-off pinion of a driving mechanism for the program plate which is located below the bottom plate, and wherein the bottom plate is so recessed in the region of the support sleeve in a direction towards the driving mechanism, as to form a hollow or depression.
2. Discussion of the Prior Art
Arrangements of the foregoing kind are generally known in the art. Thus, from the disclosure of German Laid-open Patent Application No. 24 08 581 there can ascertained a timer with a program plate which is supported on a support sleeve. The support sleeve is hereby fixedly applied on a bottom plate, which restricts the space available for the driving mechanism in a direction towards the program plate. In the region of the base of the support sleeve, the bottom plate is recessed in the direction towards the driving mechanism so as to form a hollow depression about the support sleeve. In the area of this hollow depression, the bottom plate incorporates a hole therethrough for a drive take-off pinion of the driving mechanism which operates the program plate through a gear unitarily connected with the program plate.
However with regard to the kind of security against any axial displacement of the program plate on the support sleeve, nothing is disclosed in German OS No. 24 08 581. Nevertheless, it is quite apparent, that there must be provided such a securing arrangement. The location of such securing arrangement below the program plate in the region of the hollow depression is, however, subject to considerable problems inasmuch as any accessibility thereto is extremely restricted. When, in contrast therewith, there is employed as a securing arrangement a form-fitted locking device which is effective in one direction, for the support of the program plate, then it is no longer possible to provide for the non-destructive disassembling of the program plate, or only possibly with the use of a suitable specialized worktool.
Additionally, in a construction pursuant to, German OS No. 24 08 581, because of the formation of a hollow depression which extends essentially over the diameter of the program disc, and which appreciably reduces the space available for the driving arrangement, leads to an increase in the constructional height of the timer.
A further problem which is encountered in timers which are constructed in that manner, when they are to be utilized as built-in components which, when required by the assembly, on the side of the surface of the bottom plate facing the program plate, the marking applied thereon for the recognition of the rotational position of the program plate is covered. Consequently, a new marking must be provided on the apparatus into which the timer is built-in, at a definite location; in essence, coinciding with the applicable switching points of the program plate in order to achieve a correlation between the switching points and with the set actual time.